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Foreign aquatic plants invade county lakes

Beth Concepcion photo Bill Tyson, Effingham County coordinator for agriculture and natural resources for the University of Georgia Cooperative Extension, inspects plant life to determine if it is Eurasian Water-milfoil.

Beth Concepcion photo Bill Tyson, Effingham County coordinator for agriculture and natural resources for the University of Georgia Cooperative Extension, inspects a lake in the southern part of the county for Eurasian Water-milfoil.

Bill Tyson plunged his hand into the water in a lake in southern Effingham County and pulled out what looked like seaweed. He stuck the aquatic plant into a Ziploc bag full of water and looked closely at the specimen, counting whorls of leaflets around the stem.

After counting four leaflets, Tyson, who is the Effingham County coordinator for agriculture and natural resources for the University of Georgia Cooperative Extension, pronounced the plant Eurasian Water-milfoil.

“I’m not 100 percent sure, but I’m pretty confident,” he said.

It’s the first official case reported in Effingham or Chatham counties, though Tyson said the plant has been in the area for a while, along with its sister plant, Variable Water-milfoil.

“The only way to tell is by counting the leaflets,” said Tyson. Eurasian Water-milfoil has four to five leaflets in a whorl, while Variable Water-milfoil has six.

Both kinds of milfoil are a problem. The plants compete with native plants for resources, reduce oxygen levels in the water, which kills fish, create stagnant water perfect for mosquitoes, and put a damper on recreational activities.

“It’s not a very good place to go swimming now, I can tell you that,” said Teresa Moran, who lives on the lake.

The warm, clear water in the county’s many freshwater lakes provides a good environment for the invasive species.

“Once it starts warming up,” Tyson said, “stuff starts growing.”

The plant, which is native to Europe, Asia and northern Africa, was discovered in Lake Erie in Canada in 1961. It likely was introduced through the aquarium trade or in the ballast water of ships, according to a fact sheet distributed by the Center for Invasive Species and Ecosystem Health. Since then it has spread through much of the United States.

It’s one of many invasive species monitored by the UGA Center for Invasive Species and Ecosystem Health in a partnership with the Department of Natural Resources. Karan Rawlins, invasive species coordinator, said her office is keeping an eye on the hundreds of non-native species of plants and insects creeping through Georgia.

“The most aggressive native species is better than any of the non-native species,” she said.

Most people think kudzu is the main problem in Georgia, but Rawlins said there’s 17 times more privet in Georgia’s forests. It grows into the forest canopy and native insects don’t recognize it as food. The lack of insects in the forest ultimately reduces the food supply for the songbird population.

Tyson said he often helps farmers control a new insect — the kudzu bug — which threatens soybean crops. It was first noted in north Georgia in 2009 and spread south.

“Invasives affect everything,” said Rawlins. “There is not a thing in our life that isn’t affected.”

Yet humans are the reason these invasive plants and insects are here in the first place.

“This knowledge of invasives is relatively new,” Rawlins said. “In the last 10 years, people have been most aware of what we’ve done to ourselves.”

In the case of the milfoil, Tyson said the only cure for the invasion — likely caused by the plant hitching a ride on geese — is a cocktail of herbicide or, ironically, the addition of sterile grass carp (a non-native species) to the lake to eat the plant.

“It depends on how much you want to spend, how much work is involved,” said Tyson.

For Moran, who noticed the explosion of milfoil about a month ago, the solution isn’t clear.